Bar code stencil and method of use

ABSTRACT

A bar code identification stencil for uniquely identifying a plurality of articles. The stencil includes a carrier strip which carries an identification code. The identification code is formed of a plurality of spaced a part markers which are used to form a machine readable bar code. The bar code is unique for each of the plurality of articles to be identified.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to the field of identification barcodes and scanners and more particularly, is directed to a bar codestencil and method of using such a stencil to integrally embed a barcode into an article during its manufacture. The stencil may also beused in a post production or after market identification procedure forbar code marking of articles.

[0002] The development of modern bar codes began in the 1940s inresponse to the food industry's need for a reliable and economicalsystem for inventory control and for automatically reading productinformation at grocery store check outs. The first patent to issue onsuch a system is believed to be U.S. Pat. No. 2,612,994 entitled“Classifying Apparatus and Method” and which issued on Oct. 7, 1952.

[0003] Although the coding system used in the '994 patent relied on aseries of concentric circles to encode the identification information,the original coding approach developed by the inventors was a series ofnarrow and wide vertical lines much like present day bar code systems.Early implementations of the concentric circle approach provedunreliable however, as the circles were difficult to print withoutsmearing. Smeared circles introduced reading errors when scanned andthus were unacceptable. The use of vertical bars eliminated the smearingproblem and associated scanning errors.

[0004] Since the adoption of the Universal Product Code (UPC) in 1973,bar codes have proliferated to virtually all areas of article andproduct identification. Bar codes are now widely recognized as aneconomical and reliable identification system.

[0005] Over the years, a number of different versions of the UPC barcode have been developed. Version A is one of the most popular and isillustrated in FIG. 1. The Version A format includes a plurality ofspaced vertical bars 1 which form the bar code and a plurality of humanreadable digits which correspond to the bar code, i.e, “0 25528 43507 3”as indicted by reference number 2.

[0006] As shown in FIG. 1, the code is divided into 12 digits, with thefirst digit 3 being usually a “0”. The next five digits 4 are assignedto the product manufacturer by the Uniform Code Council and thus serveto identify the manufacturer. Accordingly, all of the bar codes for thesame manufacturer will have this same five digits. The next five digits5 represent the item identification code given to a particular productby the manufacture. Thus, 99,999 products can be uniquely identified.The final twelfth digit 6 is a check digit which is used by the bar codescanner to confirm the accuracy of the scan.

[0007] Each of the human readable digits is encoded into the code usinga two-part binary coding system as indicated in the table below: CodeKey Digit Left Right Value Binary Code Binary Code 0 0001101 1110010 10011001 1100110 2 0010011 1101100 3 0111101 1000010 4 0100011 1011100 50110001 1001110 6 0101111 1010000 7 0111011 1000100 8 0110111 1001000 90001011 1110100

[0008] Each “1” in the key code is represented by a black bar 7 asillustrated FIG. 1 and each “0” in the key code is represented by whiteline or space 8. There is a center code of four lines (binary digits01010) which bisect the bar code. On the left side of the bar code, theLeft Binary Code digits from the above table are used and on the rightside of the bar code, the Right Binary Code digits from the table areused. This mirror image coding technique allows the scanner to read thenumber code in either direction. Start and stop codes are used by thescanner to set the width of the binary digits within the bar codesymbol. The scanner also uses the check digit to calculate a check sumas is know in the art. If the correct check sum is not calculated, thebar code read is rejected.

[0009]FIG. 2 is a further illustration of a typical UPC bar code withits constituent parts labeled.

[0010] As a testament to the popularity of bar code use, the UPC barcode is scheduled to be phased out by the year 2005 because its 12-digitlength will no longer be sufficient to handle the demand for bar codes.In its place, the United States is expected to adopt a version of theEuropean Article Numbering (EAN) system. The EAN bar code system hasthirteen digits and can thus accommodate substantially more productidentifications than the UPC.

[0011] The traditional printed bar code system continues to serve itsoriginal purpose of grocery store inventory control and check out verywell. Bar codes formed of conventional two-dimensional printed bars workwell where the article to be labeled is not subject to a harshenvironment and the bar code label is not likely to be rubbed off orsmeared over so that it can not be read.

[0012] The food industry serves as an ideal environment for conventionalbar codes. Bar codes used for food labeling are unlikely to be subjectedto harsh environments due to the inherent need to prevent adulterationand damage to the food package. Thus, the bar code label is not likelyto become damaged or unreadable.

[0013] The bar code system has in some respects however, become thevictim of its own success. Today, attempts are being made to use barcodes in many environments in which a conventional printedtwo-dimensional bar code, such as the one used for food products, cannot be used. One such environment is the tire manufacturing industry.

[0014] U.S. Pat. No. 5,160,383 assigned to Goodyear Tire & Rubberdiscloses one example of the use of a bar code labeling technique in thetire industry. According to the patent, it is important that a tirelabel be highly durable so that it may still be read after many years oftire service and multiple retreading. The patent also notes that serialnumbers can be molded into tire side walls but that doing so is laborintensive and costly. Thus, Goodyear sought to improve upon conventionaltire labeling systems by attaching an identification label to the rubberinter lining of an uncured tire. The label is made of two materialswhich are co-curable with the rubber of the tire. The tire is then curedusing a conventional curing process which results in the label becomingpermanently affixed to the inside of the tire.

[0015] Goodyear also is the assignee of U.S. Pat. No. 4,625,101 whichdiscloses a method of molding a bar code configuration onto the sidewallof a tire. The bar code configuration has a plurality of slopedreflective surfaces which allow more flexibility in locating the barcode scanner without adversely effecting the accuracy of the scan. A barcode plate mold insert is used to mold the bar code configuration intothe side wall of the tire during the vulcanization process.

[0016] Another technique for labeling a tire is disclosed in U.S. Pat.No. 4,941,522 assigned to the Yokohama Rubber Company. The Yokohamaapproach involves an improved bar code plate mold insert which is alsoused to mold a bar code into a side wall of the tire during thevulcanization process. The improved plate is said to solve the problemof deterioration of the tire's resistance to weather in the area of themolded bar code.

[0017] Like the tire manufacturing industry, bar code labels also havegreat utility in other harsh environments as well. For example, domesticmetal casters cast and ship millions of tons of product each year. Aneffective way to identify each product for tracking and inventorycontrol purposes is to label it with a bar code. Because casts usuallyare subjected to a post casting process to finish and shape them totheir final form, a conventional printed bar code label is oftendifficult to apply to a casting surface and is also subject to beingrubbed off or covered over during the subsequent finishing process.Moreover, a printed bar code label is likely to deteriorate over time,well before the end of the life of the cast it self, making the bar codedifficult or impossible to read.

[0018] Ideally, an identification bar code will be embedded into thearticle during the manufacturing process. Doing so, avoids thepossibility of mis-identification, i.e., the wrong bar code beingapplied, in a subsequent labeling step.

[0019] In order to improve the durability and readability of bar codesin harsh environments such as casting, a three dimensional bar codeconstruction was developed. An end view of a portion of such a bar codeis illustrated in FIG. 3. Each bar has a width 30 and a height 31. Thedistinguishing feature of this type of bar code is its height 31. Thebar code is scanned by a three dimensional bar code reader which detectsthe presence or absence of a bar based on its height rather than itscontrast as a conventional two dimensional bar code reader does. Thus, athree dimensional bar code can be read when no contrast is available.Three dimensional bar code readers are known in the art, and include thereaders manufactured by Sensis Corporation for reading Bumpy Bar Codes™.

[0020] Three dimensional bar codes have proved to be a much betterchoice in some situations as they will not easily rub off, smear, peelor vanish. They can be painted over or the article on which they areplaced can be subjected to various treatment processes without thereadability of the bar code being adversely affected. Three dimensionalbar codes are also useful where a traditional printed bar code labelwill not adhere to the surface of the article to be labeled.

[0021] The use of bar codes during manufacture for work-in-processtracking, inventory control, work piece routing, etc., has become avaluable tool. Embedding the bar code into the article during itsmanufacture is the most expedient and cost effective identificationsystem. However, due to the harsh environments in which manymanufacturing processes occur, embedding a bar code into a manufacturedarticle can present a challenge. The challenge usually involvesovercoming the ill effects caused by the very high temperatures andpressures that are present in, e.g, cast and molding processes. Thus,there is a need in the art for a bar code stencil which can be easilyand reliably used for embedding bar codes into articles during theirmanufacture.

SUMMARY OF THE INVENTION

[0022] Accordingly, it is an objective of the present invention toobviate the above-noted shortcomings and disadvantages of presentmethods of marking an article with a bar code.

[0023] It is a further objective of the present invention to provide animproved method of bar code marking which is more reliable and costeffective than conventional methods.

[0024] It is a still further objective of the present invention toprovide an improved method of bar code marking which is economical toimplement and simple in operation.

[0025] It is a still further objective of the present invention toprovide an improved method of bar code marking which can be used inharsh environments.

[0026] It is a another objective of the present invention to provide animproved method of bar code marking which can be used to embed a barcode into a metal cast article during the casting process.

[0027] It is a further objective of the present invention to provide animproved method of bar code marking which can be used to embed a barcode into a molded article during the molding process.

[0028] It is a another objective of the present invention to provide animproved method of bar code marking which can be used to bar code anarticle in the field.

[0029] It is still another objective of the present invention to providea bar code stencil which allows all of the above noted objectives toachieved.

[0030] The bar code stencil of the present invention, allows theembedding of a permanently formed bar code into a cast metal or moldedpart at the point of manufacture. The stencils can have sequentiallynumbered bar codes that are placed directly into a mold cavity. Once inthe cavity, the mold is closed and filled as normal with the desiredmaterial. The result is a bar code that is literally molded or cast ontoor into the surface of the finished article out of the same material asthe article.

[0031] The bars which form the bar code take on a raised,three-dimensional form that has all the strength and visualcharacteristics of the parent article material and can be read throughgrease and grim unlike the bars on a printed label.

[0032] Several variations of the stencil can be provided for differentarticle manufacturing processes. Variations in the stencils areprimarily based on the temperature and pressures that a particularprocess requires when generating an article. For example, casting a barcode into the side of an iron engine block requires a stencil capable ofwithstanding in access of 3,000 degrees F. with very little pressure. Astencil for use in molding a bar code integral to an injection moldedarticle, however, requires a material capable of 5,000 degrees F. and3,500 PSI.

[0033] The stencil of the present invention can be sequentially encodedwith any number of digits in any x-dimension and with all of the barcode symbologies in use today.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The novel features of the present invention are set out withparticularity in the appended claims, but the invention will beunderstood more fully and clearly from the following detaileddescription of the invention as set forth in the accompanying drawingsin which:

[0035]FIGS. 1 and 2 are illustrations of a UPC bar code;

[0036]FIG. 3 is an illustration of a three dimensional bar code;

[0037]FIG. 4 is an illustration of a bar code stencil in accordance withthe present invention;

[0038] FIGS. 5-9 are various bar code cross sections;

[0039]FIG. 10 is a side view of a bar code stencil in accordance withthe present invention illustrating the use of a double back adhesivetape;

[0040]FIG. 11 is a side view of a bar code stencil in accordance withthe present invention illustrating the use of an over laminate; and

[0041]FIG. 12 is a top view of a bar code stencil in accordance with thepresent invention which is adapted for use in a plastic mold.

DESCRIPTION F THE PREFERRED EMBODIMENT

[0042] A preferred embodiment of the present invention will now bedescribed with further reference to accompanying drawings.

[0043]FIG. 4 illustrates one embodiment of a bar code stencil accordingto the present invention. The stencil includes a carrier strip 40 withan area 41 in which a plurality of bar code marker locations 42 areprovided along carrier strip 40. The stencil may be used with virtuallyany bar code symbology with out departing from the spirit and objectivesof the invention.

[0044] Carrier strip 40 is generally of rectangular shape and its sizewill depend on the symbology used and the particular application forwhich the stencil will be used. Applicant has found that a size ofapproximately 3½ inches long by {fraction (3/4)} inches wide and 0.100inches thick to be a convenient size. As discussed below, the size ofthe stencil may also be a consideration of the starting size of thesheet material from which the stencil is made.

[0045] Carrier strip 40 may be made from a number of materials know inthe prior art, including materials which have a fiber re-enforcementwith a binding agent to contain the fiber re-enforcement. Such materialsmay typically be fabricated in sheets of approximately 36×36×0.100inches and can usually be custom sized to a user's specification.

[0046] The type of material used to make carrier strip 40 will alsodepend on the structural integrity requirements of the stencil duringmanufacture of the article for which the stencil will be used toidentify. For example during casting with molten metals, temperaturescan reach 3,500 degree F. For use in such an environment, carrier 40 maybe made from a ceramic fiber material in order to provide the requiredresistance to high temperature. In some applications, carrier strip 40may also be subjected to pressures as high as 5,000 PSI, either positiveor negative. Thus, the material used to make carrier 40 must be selectedaccordingly.

[0047] In an environment where the stencil will not be subjected totemperature extremes, for example, in an after market label process,carrier 40 may be made with lower temperature grade materials.

[0048] At selected marker locations 42, a void is formed in carrier 40in accordance with the particular bar code symbology to be used. Thesevoids can comprise cut outs which are formed fully through carrier 40 orcan be mere depressions created by a press or stamp. FIG. 5 is a crosssection of one void formed by a cut out and FIG. 6 is a cross section ofa void formed by a depression. Cut outs may ideally be formed in carrier40 using water jet cutting technology.

[0049] Applicant has discovered that the particular profile of the voidhas a great deal of impact on the durability of the three dimensionalbar code formed when the stencil is used in a casting or moldingoperation. Applicant has learned that a three dimensional bar having across section as illustrated in FIG. 7 has greater strength anddurability than one having a rectangular cross section as shown in FIG.8. Thus, voids 42 are ideally formed in carrier 40 with a cross sectionas illustrated in FIG. 9.

[0050] When used in a cast or mold, the stencil may be attached to asurface of the cast or mold using a number of attachment means,including fastening clips, ties and epoxy. Carrier 40 may also be formedof a material which has been magnetized so that the carrier willnaturally stick to the surface of, e.g., a mold. Carrier 40 may also beprovided with a double back adhesive 11 for attachment purposes as shownin FIG. 10.

[0051] In the case where the stencil is attached using epoxy, thestencil may be provided with an over laminate on the opposed side inorder to prevent the epoxy from entering the cut outs which form the barcode bars. FIG. 12 illustrates this application where reference number20 refers to an interior surface of, for example, a mold, to which anepoxy material 21 is applied to hold stencil 23. An over laminate 22prevents the epoxy material from entering the cut out.

[0052]FIG. 12 illustrates a bar code stencil which has been formed bydepressions 30 at selected marker locations. The stencil also includeshuman readable digits 31 which correspond to the bar code. Note that oneend of each bar and digit character meet at a common runner 32 and thatthe opposite edges correspond with the edges of the stencil. Such aconstruction allows the stencil to be easily used in a plastic mode without flashing or incomplete formation of the bar code or human readabledigits.

[0053] It should be obvious from the above-discussed apparatusembodiment that numerous other variations and modifications of theapparatus of this invention are possible, and such will readily occur tothose skilled in the art. Accordingly, the scope of this invention isnot to be limited to the embodiment disclosed, but is to include anysuch embodiments as may be encompassed within the scope of the claimsappended hereto.

I claim:
 1. A bar code identification stencil for uniquely identifying aplurality of articles, said stencil comprising: a carrier strip forcarrying an identification code; and an identification code carried bysaid carrier strip, said identification code being formed of a pluralityof spaced a part markers of generally elongated shape formed in saidcarrier strip, said markers forming a machine readable bar code which isunique for each of said plurality of articles to be identified.
 2. A barcode identification stencil according to claim 1, wherein said carrierstrip is generally rectangular in shape.
 3. A bar code identificationstencil according to claim 1, wherein said carrier strip is generallyuniform in thickness.
 4. A bar code identification stencil according toclaim 1, wherein each of said markers are generally parallel to eachother.
 5. A bar code identification stencil according to claim 4,wherein each of said markers are generally of the same length.
 6. A barcode identification stencil according to claim 1, wherein each of saidmarkers is formed by a depression in said carrier strip.
 7. A bar codeidentification stencil according to claim 1, wherein each of saidmarkers is formed by a cutout in said carrier strip.
 8. A bar codeidentification stencil according to claim 7, wherein each of saidcutouts extends fully through said carrier strip.
 9. A bar codeidentification stencil according to claim 1, wherein said carrier stripis generally flexible in order to conform to the shape of an articlebeing identified by said identification stencil.
 10. A bar codeidentification stencil according to claim 1, wherein said carrier stripis made from a fibre reinforced material with a bind agent forcontaining said fibre reinforced material.
 11. A bar code identificationstencil according to claim 1, wherein said carrier strip is made from amaterial which can withstand a temperature of at least 3,500 degrees F.without being damaged to the point that said identification stencil isno longer useful for its intended purpose.
 12. A bar code identificationstencil according to claim 1, wherein said carrier strip is made from amaterial which can withstand a pressure of at least 5,000 PSI withoutbeing damaged to the point that said identification stencil is no longeruseful for its intended purpose.
 13. A bar code identification stencilaccording to claim 1, wherein said carrier strip is made from a materialwhich can withstand a vacuum of at least 30 inches of mercury withoutbeing damaged to the point that said identification stencil is no longeruseful for its intended purpose.
 14. A bar code identification stencilaccording to claim 1, wherein said identification code is formed of aplurality of identification code elements and wherein said carrier stripincludes a plurality of identification code element locations, saidmarkers being formed at selected ones of said element locations.
 15. Abar code identification stencil according to claim 14, wherein thepresence or absence of a said marker at a said element location forms aunique identification code for said identification stencil.
 16. A barcode identification stencil according to claim 1 further comprising anattachment element for attaching said identification stencil to anarticle to be identified by said identification stencil.
 17. A bar codeidentification stencil according to claim 16, wherein said attachmentelement includes an adhesive tape.
 18. A bar code identification stencilaccording to claim 16, wherein said attachment element includes adouble-back adhesive tape with a first side of said adhesive tapeadhered to said carrier strip and a second side of said adhesive tapeadhered to a release liner.
 19. A bar code identification stencilaccording to claim 1, wherein said carrier strip is adapted to beattached to an interior surface of a cast used to cast the article to beidentified by said identification stencil using an attachment material.20. The method of claim 19, wherein said carrier strip further includesa barrier layer for preventing said attachment material from coming intocontact with said carrier strip.
 21. A bar code identification stencilaccording to claim 1, wherein said carrier strip is adapted to beattached to an interior surface of a mold used to mold the article to beidentified by said identification stencil using an attachment material.22. A bar code identification stencil according to claim 6, wherein saidcarrier strip includes runner and gate depressions through which amolding material can be supplied to fill said marker depressions duringan injection molding process.
 23. A bar code identification stencilaccording to claim 22, wherein said gate depression is formed along oneedge of said carrier strip.
 24. A bar code identification stencilaccording to claim 23, wherein said gate depression is connected to saidrunner depression.
 25. A bar code identification stencil according toclaim 24, wherein said runner depression is connected to each of saidmarker depressions.
 26. A bar code identification stencil according toclaim 25, wherein at least one end of said marker depressions terminatein an opening at an edge of said carrier strip.
 27. A bar codeidentification stencil according to claim 6, wherein said carrier stripfurther includes human readable symbols which correspond to saididentification code.
 28. A bar code identification stencil according toclaim 27, wherein said human readable symbols are formed as depressionsin said carrier strip.
 29. A bar code identification stencil accordingto claim 28, wherein said runner depression is connected to each of saidsymbol depressions.
 30. A bar code identification stencil according toclaim 29, wherein an edge of each of said symbol depressions forms anopening at an edge of said carrier strip.
 31. A method for uniquelyidentifying a plurality of cast articles using a machine readable barcode number integrally cast into said article during the castingprocess, said method comprising the steps of: providing a bar codeidentification stencil having a carrier strip which carries anidentification code, said identification code being formed of aplurality of spaced a part voids and being unique for each of saidplurality of articles to be identified; attaching said stencil to aninterior surface of the cast used to cast said articles; filling saidcast with casting material to cast said article and to fill said voidsto thereby form said bar code number; and using a different said stencilfor each of said plurality articles to be cast.
 32. The method of claim31, wherein said carrier strip includes an attachment element forattaching said identification stencil to said interior surface of saidcast.
 33. The method of claim 32, wherein said carrier strip is adaptedto be attached to said interior surface of said cast using an attachmentmaterial.
 34. The method of claim 33, wherein said carrier strip furtherincludes a barrier layer for preventing said attachment material fromcoming into contact with said carrier strip.
 35. A method for uniquelyidentifying a plurality of molded articles using a machine readable barcode number integrally molded into said article during the moldingprocess, said method comprising the steps of: providing a bar codeidentification stencil having a carrier strip which carries anidentification code, said identification code being formed of aplurality of spaced a part voids and being unique for each of saidplurality of articles to be identified; attaching said stencil to aninterior surface of the mold used to mold said articles; filling saidmold with molding material to mold said article and to fill said voidsto thereby form said bar code number; and using a different said stencilfor each of said plurality of articles to be molded.